Let's see, counterarguments to Fahrenheit: AI gandma, simon says, aliens, the flashback gameplay and last, but not the least, the ending. Before you say they didn't have enough time to finish it, AI grandma and aliens were always going to be in the story...
As for Heavy Rain, see the plot holes section for some fun reading material. Also, Cage still couldn't keep all his craziness to himself with Jayden's futuristic crap(he did show remarkable restraint, I'll give you that). Not to mention some of the bad voice acting(JAAASOOOON and the prostitute come to mind) and the tank controls.
To actually improve the "genre", you would need to have some actual writers and editors make the story and keep Quantic Dream as far away from it as possible.